We report the synthesis, characterization and spectroscopic results of the Cu(II) complexes [Cu(pabt)(OH 2 )](ClO 4 ) ( 1 ), [Cu(pabt)(Imz)](ClO 4 ) ( 2 ), [Cu(pabt)( N -MeImz)](ClO 4 ) ( 3 ), [Cu(pabt)Cl] ( 4 ), [Cu(pma)Cl] ( 5 ), [Cu(pdta)Cl]Cl ( 6 ) and [Cu( reduced -pdta)Cl]Cl ( 7 ), (Hpabt = N -(2-mercaptophenyl)-2′-pyridylmethylenimine, Hpma = N -(2-pyridylmethyl)-2-mercaptoaniline, pdta = 2,2′-di(pyridyl-2-methyleneimine)diphenyl disulfide, reduced -pdta = 2,2′-di(pyridyl-2-methylamine)diphenyl disulfide, Imz = imidazole, N -MeImz = N -methylimidazole). Electronic spectra of all these compounds display strong LMCT bands in the visible region mainly associated with S → Cu(II), and consistent with TDDFT results. A four-line EPR pattern originating from the interaction of the unpaired electron with the central 63/65 Cu nucleus (I = 3/2, natural abundances: 63 Cu, 69.17%; 65 Cu, 30.83%) with the isotropic coupling constant ( A iso ) values of 80 ± 1.5 G at RT for all these complexes suggests monomeric nature in solution. The redox behavior of these compounds show either nearly reversible or quasi-reversible Cu(II)/Cu(I) couple with redox potentials within the range −0.08 to −0.20 V versus Ag/AgCl. Some of these compounds show strong intercalative DNA binding and its complete cleavage. 1 – 3 exhibit remarkable cytotoxicity against C6 glioma cell line and human cervical cancer HeLa cell line. IC 50 values of 2 and 3 for the cervical cancer HeLa cell line reveal that they exhibit higher cytotoxicity than many reported Cu(II) compounds. [ABSTRACT FROM AUTHOR]